This invention relates to a forage harvester header and more particularly to an upper stalk control for controlling the orientation of crop stalks as they are being conveyed by the header into the crop receiving throat of the harvester.
Forage harvesters for operation in row-planted crop stalks such as corn are provided with multirow headers for cutting and conveying the crop from its standing position in the field into the crop receiving throat of the harvester for processing. One conventional component of such headers is an upper stalk control or guide for engaging the upper portion of the crop stalks as the butt ends of the stalks are being conveyed rearwardly in the crop receiving passageways of the header so that the butt end of the crop stalks are fed into the throat of the harvester in advance of the upper portion of the crop stalks. Such stalk controls are typically comprised of a transverse member disposed generally above and forwardly of the crop exits of the conveyor passageways and two outwardly and forwardly diverging arms attached to the respective ends of the transverse member. The arms are generally disposed parallel to and above the outer dividers or sides of the header and function to converge the upper portions of the stalks together as they are moved toward the rear of the header until the upper portions engage the transverse member. Upon engagement of the upper stalk with the transverse member, the butt end of the stalk is continued to be fed rearwardly in one of the conveying passageways and enters the crop receiving throat of the harvester in advance of the upper stalk portion. Examples of stalk controls for three- and four-row headers are disclosed in U.S. Pat. No. 3,791,117 and U.S. Pat. No. 4,106,270, respectively.
A modification of this type of stalk control for a three-row header is disclosed in U.S. Pat. No. 3,796,029. The modified type is the same as that described above except that an additional pair of arms is disposed centrally of the outer pair of arms. The arms extend above and are generally parallel (1) to the crop divider separating one of the outer crop receiving passageways and the center crop receiving passageway and (2) to the crop divider separating the other outer crop receiving passageway and the center crop receiving passageway, respectively. The inner pair of arms functions with the outer pair of arms to form individual channels for the upper portion of the crop stalks in each row corresponding to the lower passageways so that the crop in each row is separated from and is conveyed and converged somewhat independently of the others.
It is also known to use a stalk control of the unmodified type with the header disclosed and claimed in U.S. application, Ser. No. 74,265, cross-referenced above. It was found that headers of this type were subject to clogging and to entanglement of the crop stalks as the stalks were being conveyed through the crop receiving passageways toward the crop receiving throat of the harvester.